1. Field of the Invention
The present invention regards the shoe industry and more specifically it concerns a sole provided in a single moulding made of non-rigid but elastic material having one or more vertical elements folded over each other in such a manner that the horizontal extension thereof mechanically adapts the width of the sole, to the different width of the assembly lasts of the upper of a shoe and also allowing adapting the width of the sole to the variation of the conformation of the feet, generated by the daily swellings thereof leaving the normal flexibility and comfort of the shoe unaltered with the possibility for the user to stabilize the width of the sole to the possible deformation of the foot by injecting—from outside into the widened internal cavity—a foamed two-component fluid material which, upon solidification within a few minutes, blocks any widened pan of the sole to the conformation or to the deformation of the feet of the user.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Used in the construction of a shoe are assembly lasts having lengths for predetermined sizes with the general effect that the user can select—on the market—shoes that are suitable for the length of the feet thereof hut not always suitable to the transverse width of the same.
This leads to clear discomfort for the user even due to the known fact that the width of the human foot never has a clearly determined ratio with the length thereof and that the morphology of the right foot of a person is generally different from the left foot thereof, leading to the fact, that the shoe made using identical assembly lasts for both feet may perfectly adapt to the right foot but not to the left foot or vice versa.
It is known that the feet are subjected to daily swellings due to different reasons, hence the possibility of simultaneously adapting the upper and the sole to the variable conformation thereof makes the shoe much more comfortable.
Furthermore, there currently arises technical and aesthetic-needs which require assembly lasts of the shoe having, different lengths of the plantar arch of the sole and/or of the sole which require soles having the width of the gluing base compatible with those of the former, hence leading to the shoe makers making as many sole moulds as the various widths of the assembly lasts, with the ensuing increase of the costs of production of the shoe.
Currently, there are various patents providing for adapting the shoe to the conformation of the foot and to the possible deformations thereof.
The Italian patent under application No. BO2002A000816 dated Mar. 22, 2004, having the title “A method for producing shoes and a shoe obtained by this method”, describes and claims a process for making a shoe adaptable—in width—to the conformation or deformation of the foot of the user, consisting in fixing the upper to the sole at some predetermined points and introducing—into the interspace left vacant—a transversely-extensible, elastic band when the shoe is fitted so as to adapt the upper to the conformation or deformation of the foot of the user.
The above mentioned patent reveals the drawback lying in the fact that the stabilization of the adaptation of the sole to the conformation of the foot as described and claimed therein requires a subsequent gluing of the unglued interpsaces of the upper to the sole and the milling of the initial greater width of the sole with respect to that of the upper to actually adapt it to the width of the foot of the user.
The patent under application No. PCT/FR/02/01366 dated Apr. 22, 2002 extended in the US under U.S. Pat. No. 7,155,845 B2 having the title “Sole with extensible structure footwear equipped with same and method for mounting same” describes and claims the structure of a sole whose transverse extension is obtained through insertion—by means of moulding or gluing—of a deformable insert into the sole base made of shape memory elastic material provided with—in the underlying part thereof—one or more lugs countersunk in corresponding openings of the base sole.
A similar solution was also applied by the patent under application No. PCT/ES/05/0000018 of the Jan. 14, 2005 on behalf of Hergar claiming the priority rights of the Spanish patent No. ES U 2004736 dated Mar. 25, 2004 having the title “Calcado e sola ergonomicos auto-ventildos” whose adaptation of the shoe and of the sole to the conformation of the foot of the user is determined by a series of parallel longitudinal grooves arranged staggered with respect to the others at the level of the sole so as to obtain a structure of the bellow type which allows a transverse elastic, deformation of the sole also facilitated by an elastic body inserted into an insole.
The US patent No. 2005/0210710 A1 having the title “Footwear system having a sole adaptable to different dimensions of shoes” describes and claims a system of two soles of different dimensions the second of which is adaptable to the dimensions of the first and it is provided with a hollow part so as to be able to adapt to the dimension of the second sole.
More recently, the problem regarding the adaptability of the shoe to the conformation or deformations of the foot of the user was addressed by the patent under application No. PCT/IT-2005/000071 having the title “Shoe having an inner adaptable surface on which the wearer's foot rests” wherein the adaptability of the shoe to the various conformations of the foot of the user was resolved by providing the sole with an insole provided in a first step-made of rubber material and provided in which is a perpendicular and truck-shaped groove introduced into which is the more elastic material which, in a second step, due to the pressure exerted by the foot, overflows from such trunk-shape leading to the adjustment of the shape of the shoe to the conformation of the foot of the user.
Another solution for the adaptability of the shoe to the conformation of the foot of the user was described and claimed in patent US 2007/0039208 A1 having the title “Adaptable shoe having art expandable sole assembly” which, besides providing for the insertion of elastic elements into the upper of the shoe to adapt it to the conformation of the foot, it describes and claims a system which also makes the sole extensible—in width—to adapt it to the width of the upper by using an intermediate sole made of soft material and housed in the external sole; said intermediate sole is provided with cavities on the front and central parts of the sole intended to house the elements which facilitate the transverse extension due to the pressure of the sole adapting it to the conformation of the foot of the user.
Said patent expressly refers [0055 page 5] to the solution described and claimed in patent WO 2006/087737 A1 having the title “Shoe-with adjustable sole” which describes and claims a sole inserted into which are stiff elements alternated with deformable elements which, selected by the user when buying the shoe according to the conformation to the feet thereof cause the widening of the sole and of the shoe to suit the needs thereof.
Though said system allows providing a shoe whose dimensions match the conformation of the foot of the user, they reveal the drawback lying in that the presence of stiff elements within the shoe make it not perfectly fitting and limit flexibility thereof with the ensuing effect of making it uncomfortable.
Another drawback of the solution subject of the application PCX WO 2006/087737 regards the need, of providing—for each pair of shoes—a plurality of innersoles having stiff elements of various shapes and dimensions to offer to the buyers, with the ensuing negative effect of increasing the cost of production of the shoe.
All the devices described above base the transverse adaptability effect of the upper or of the sole of a shoe on the insertion, of more or less stiff stabilising elements which have the drawback of limiting and reducing the flexibility of the shoe.
On the contrary, in the invention described and claimed with the present application, the adaptation of the width of the sole to the upper occurs mechanically in the gluing step thereof and subsequently automatically due to the pressure exerted onto the upper and onto the sole by the variation of the conformation or by the deformation of the foot, the term “mechanical” widening being used to indicate, the movement—in horizontal line—determined by the pressure of the step of gluing the sole to the upper inserted to the assembly last thereof; and the term “automatic” widening of the sole is used to indicate the movement—in horizontal line—caused by pressure and by the variation of the conformation of the foot following the swelling thereof or by the deformation thereof.
The injection of a foamed two-component fluid material into an internal cavity of the sole widened by extending the vertical folded elements is provide for should the user want to permanently stabilise the width of the sole to the shoe, with the aim of keeping the degree of flexibility of the shoe unaltered and improving comfort thereof.
The comfort of the shoe that shall adapt the sole subject of the present application is ensured by the further advantage lying in the fact that the user thereof has a shoe whose sole and upper automatically adapt to the daily variable swelling of the foot thereof.
Lastly the present invention differs from the above mentioned patents due to the feet that it meets the needs of shoe makers and of the end consumer in that, by allowing the shoe makers to use a sole adaptable to the different, widths of the assembly lasts, it determines economies of cost of the production process and provides the user with a more comfortable and flexible shoe with respect to those currently available in the market.